2007.01.31 19:04 "Re: [Tiff] 16bit grayscale with colormap", by Bob Friesenhahn

Hmmm... I go the same message with ImageMagick's imdisplay.exe. Maybe the error message is just a bit too un-exact: the color map is there (according to the dump), maybe it's just about the unexpected length of 192kB instead of 256 byte? The values of the dump represent exactly what I have in the color map (repeated ASCII "0123456789ABCDEF").

Does GraphMagick do a length check for that tag?

No, initially GraphicsMagick just requests the tag from libtiff. It is libtiff producing the error before GraphicsMagick has a chance to do anything with it. Maybe libtiff includes length checks or maybe there is some other issue. A wrong length could be used to 'trojan' or crash some applications so assuring the correct length is important.

Joris has a TIFF inspection tool which should help to diagnose the issue with your file.

Bob
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Bob Friesenhahn
bfriesen@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer, http://www.GraphicsMagick.org/